| 摘要 |
PURPOSE:To prevent decrease of image density and increase of fog by incorporating a toner powder and a fine powder of a polymer obtained by the soap-free polymn. method having an average particle diameter smaller than that of this toner powder to prepare a developer. CONSTITUTION:A developer contains a mixture of a toner powder, e.g., having an average particle diameter of 3-20mum and a fine powder of a polymer obtained by the soap-free polymn. method having that of 0.05-5mum, preferably, 0.1-2mum in an amt. of this fine powder of 0.01-10wt%, preferably 0.05-2.0wt% of the toner. In the soap-free polymn. method, a monomer is dispersed and emulsified in a medium, such as water, by using a specified reactive emulsifier, etc., and polymerized by adding a water-soluble initiator to form an emulsion of a polymer, and it is dehydrated, and dried to obtain a fine polymer powder. |
